Martha is constructing the circumscribed circle for △rst. she has already used her compass and straightedge to complete the part of the construction shown in the figure.
which construction could be her next step?
construct the line through points a and y.
place the point of the compass on point c and extend the compasses to point r.
place the point of the compass on the intersection of ab and cd and extend the compasses to point r.
construct the angle bisector of ∠t .